At least 82 kids and teens in the U.S. have died over the past 12 years after playing what has been called "the choking game," according to a study released by the U.S. Centers for Disease Control and Prevention.

Kids playing the game try to choke themselves or a friend in an attempt to achieve a brief "high" by cutting off the supply of oxygen to their brain. But the game can lead to death or serious injury, such as brain damage. Often times parents have no idea that their kids may be playing the game and with their lives.

"We as parents don't know what's going on," Sharron Grant of Ontario told CTV News.

Her son 12-year-old son Jesse choked himself intentionally and didn't survive.

"The children don't believe they're doing anything wrong," Grant said.

The CDC says in its report that most of the kids who have died have been boys (87 per cent) and most were between 11 years and 16 years old. The CDC found that most of the deaths occurred when a child engaged in the choking game alone.

There have been reports of the game being played in Canada as well, as well as reports of deaths, but statistics on the game in Canada have not been released.

The CDC study's lead author, Robin L. Toblin, says most parents of children who died while playing the choking game were unaware of the game, but they hope more parents will learn of it and warn their children of the dangers.

"Because most parents in the study had not heard of the choking game, we hope to raise awareness of the choking game among parents, health care providers, and educators, so they can recognize warning signs of the activity," said Toblin.

"This is especially important because children themselves may not appreciate the dangers of this activity."

Signs that a child may be engaging in the "choking game" include:

  • discussion of the game -- including other terms used for it, such as "pass-out game'' or "space monkey";
  • bloodshot eyes;
  • marks on the neck;
  • severe headaches;
  • disorientation after spending time alone;
  • ropes, scarves, and belts tied to bedroom furniture or doorknobs or found knotted on the floor;
  • unexplained presence of things like dog leashes, choke collars and bungee cords

"If parents believe their child is playing the choking game, they should speak to them about the life-threatening dangers associated with the game and seek additional help if necessary," the CDC warns.

The CDC said there were three or fewer choking game-related deaths reported each year between 1995 and 2004, the report said. But in 2005, there were 22 deaths, and 35 in 2006. Nine deaths occurred in the first 10 months of 2007; though why the numbers seemed to drop that year is unclear.

The researchers say their study probably underestimates the number of deaths, since public health authorities don't collect death data on this practice.

The website for the advocacy group GASP (Games Adolescents Shouldn't Play), reports that 65 children died in 2007 alone.

The CDC researchers relied on media reports of deaths and then investigated to confirm the cause of death. They eliminated suicides as well as deaths that may have involved "autoerotic asphyxiation", a practice of choking oneself during sexual stimulation that is usually engaged in by teen-aged or adult males.

The researchers say they would like to see more research to determine prevalence of the game and to determine the risk factors and possible methods that could reduce or eliminate choking-game play and deaths.